"They (governors) want to be seen to be standing up for their dairy farmers and I think the Government of Canada wants to be seen to be standing up for its dairy farmers", he said. The trade groups are seeking to appeal to Trump's stated interest in protecting American businesses from unfair trade practices. "Canada didn't like USA farmers supplying their processors" demand for milk proteins, so they changed the rules of the game.

In a story April 6 about a trade dispute between the US and Canada over milk, The Associated Press reported erroneously that some Canadian provinces had applied import taxes to USA imports of ultra-filtered milk.

"Dairy trade between Canada and the U.S.is important and the sectoral trade balance massively favours the US, at around 5 to 1", the letter said. Leading imports included snack foods, red meats, live animals, vegetable oils, and processed fruit and vegetables. Ultrafilitered milk is not covered by NAFTA, according to the Post article, but tensions over the issue could affect how other aspects of the trade agreement are re-examined.

The ambassador told reporters in Halifax on Wednesday that earlier written appeals from New York Governor Andrew Cuomo and Wisconsin Governor Scott Walker to the White House demanding action on the dairy file contained "factual errors" and noted the goal of his strongly-worded response was to "set the record straight".

The ambassador's letter comes after Trump weighed-in on the dispute during a visit to a Kenosha manufacturing company Tuesday.

Canada denies that its dairy policies cause losses for USA dairy farmers, and blames instead overproduction by the United States and globally, which the highly regulated Canadian system avoids.

Trump also took the opportunity to slam NAFTA, the free trade deal linking the US, Mexico and Canada, calling it a "disaster for our country".

Michael and Debbie Mullin, who have been tending to their cows for over 30 years, say they're not anxious about the future of their industry despite Trump's remarks.

Ottawa must stand up to U.S. President Donald Trump after his unexpected broadside at Canada's dairy farmers, says local Member of Parliament Gord Brown. "We have repeatedly stressed that trade must be fair and that all countries should be held accountable when they break the rules".

Weins's support was echoed by the Dairy Farmers of Canada, which said Tuesday it believed the federal government would continue to "defend" the dairy industry. Production kicked into gear long after NAFTA came into effect, in 1994, so it's not subject to the same high tariffs as other types of milk. Dairy farmers have already been crippled by years of stagnating milk prices, and one Central New York milk producer - Cayuga Milk Ingredients - has said it could lose 25 percent of its sales after investing more than $100 million in an ultra-filtered milk processing plant. Several of New York's elected officials, including U.S. Sen.

There is a sense of urgency to the campaign since all of the farms terminated by Grassland Dairy have until May 1 before their milk stops getting picked up.

Trump on Tuesday responded to appeals for help from the dairy industry during an event in Wisconsin, where he also renewed his complaints about the North American Free Trade Agreement.

"We do allow pretty significant access to the Canadian market, but we definitely do protect the rest of it", she said.